Conventionally, a camera device having a zoom function has been generally known (for example, refer to Patent Literature 1). A lens unit of such camera device is often designed in different sizes according to zoom magnification. For example, a size (a width and a height) of a lens unit for large zoom magnification (a lens unit for 30× zoom magnification) is designed larger than that for small zoom magnification (for example, a lens unit for 22× zoom magnification).
However, in a conventional camera device, when lens units for different zoom magnification have been developed individually, the development of chassis is costly, time-consuming, and labor-intensive since the chassis are individually designed for every size of the lens unit. For example, when the lens unit for 22× zoom magnification and the lens unit for 30× zoom magnification are developed individually, a chassis tailored to the lens unit for 30× zoom magnification is designed and developed while a chassis tailored to the lens unit for 22× zoom magnification is designed and developed. As described above, development efficiency of the chassis has been low in the conventional camera device.